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The radial speed-expansion speed relation for Earth-directed CMEs
Gopalswamy, N.; Yashiro, S.; Mäkelä, P.
Earth-directed coronal mass ejections (CMEs) are the main drivers of major geomagnetic storms. Therefore, a good estimate of the disturbance arrival time at Earth is required for space weather predictions. The STEREO and SOHO spacecraft were viewing the Sun in near quadrature during January 2010 to September 2012, providing a unique opportunity to…
One year in the Earth's magnetosphere: A global MHD simulation and spacecraft measurements
Kallio, E.; Palin, L.; Facskó, G. +6 more
The response of the Earth's magnetosphere to changing solar wind conditions is studied with a 3-D Magnetohydrodynamic (MHD) model. One full year (155 Cluster orbits) of the Earth's magnetosphere is simulated using Grand Unified Magnetosphere Ionosphere Coupling simulation (GUMICS-4) magnetohydrodynamic code. Real solar wind measurements are given …
The utility of polarized heliospheric imaging for space weather monitoring
Webb, D. F.; Davies, J. A.; DeForest, C. E. +1 more
A polarizing heliospheric imager is a critical next generation tool for space weather monitoring and prediction. Heliospheric imagers can track coronal mass ejections (CMEs) as they cross the solar system, using sunlight scattered by electrons in the CME. This tracking has been demonstrated to improve the forecasting of impact probability and arri…
Rating global magnetosphere model simulations through statistical data-model comparisons
Ridley, A. J.; De Zeeuw, D. L.; Rastätter, L.
The Community Coordinated Modeling Center (CCMC) was created in 2000 to allow researchers to remotely run simulations and explore the results through online tools. Since that time, over 10,000 simulations have been conducted at CCMC through their runs-on-request service. Many of those simulations have been event studies using global magnetohydrody…
Prediction of shock arrival times from CME and flare data
Nieves-Chinchilla, Teresa; Pulkkinen, Antti; Núñez, Marlon
This paper presents the Shock Arrival Model (SARM) for predicting shock arrival times for distances from 0.72 AU to 8.7 AU by using coronal mass ejections (CME) and flare data. SARM is an aerodynamic drag model described by a differential equation that has been calibrated with a data set of 120 shocks observed from 1997 to 2010 by minimizing the m…
Contamination in electron observations of the silicon detector on board Cluster/RAPID/IES instrument in Earth's radiation belts and ring current
Daly, P. W.; Klecker, B.; Pierrard, V. +10 more
Since more than 15 years, the Cluster mission passes through Earth's radiation belts at least once every 2 days for several hours, measuring the electron intensity at energies from 30 to 400 keV. These data have previously been considered not usable due to contamination caused by penetrating energetic particles (protons at >100 keV and electron…
On the role played by magnetic expansion factor in the prediction of solar wind speed
Riley, Pete; Linker, Jon A.; Arge, C. Nick
Over the last two decades, the Wang-Sheeley-Arge (WSA) model has evolved significantly. Beginning as a simple observed correlation between the expansion factor of coronal magnetic field lines and the measured speed of the solar wind at 1 AU (the Wang-Sheeley (WS) model), the WSA model now drives NOAA's first operational space weather model, provid…
Validation for solar wind prediction at Earth: Comparison of coronal and heliospheric models installed at the CCMC
Jian, L. K.; Odstrcil, D.; Riley, P. +6 more
Multiple coronal and heliospheric models have been recently upgraded at the Community Coordinated Modeling Center (CCMC), including the Wang-Sheeley-Arge (WSA)-Enlil model, MHD-Around-a-Sphere (MAS)-Enlil model, Space Weather Modeling Framework (SWMF), and heliospheric tomography using interplanetary scintillation data. To investigate the effects …
Predicting the magnetic vectors within coronal mass ejections arriving at Earth: 1. Initial architecture
Thompson, B. J.; Richardson, I. G.; Szabo, A. +6 more
The process by which the Sun affects the terrestrial environment on short timescales is predominately driven by the amount of magnetic reconnection between the solar wind and Earth's magnetosphere. Reconnection occurs most efficiently when the solar wind magnetic field has a southward component. The most severe impacts are during the arrival of a …
Ensemble Modeling of the 23 July 2012 Coronal Mass Ejection
Arge, C. N.; Henney, C. J.; Odstrcil, D. +5 more
On 23 July 2012 a significant and rapid coronal mass ejection (CME) was detected in situ by the Solar Terrestrial Relations Observatory (STEREO) A. This CME was unusual due to its extremely brief Sun-to-1 AU transit time of less than 21 h and its exceptionally high impact speed of 2246 km/s. If this CME had been Earth directed, it would have produ…